Time acquisition in a wireless position determination system
First Claim
1. In a wireless communications system including a position determination entity, a method for acquiring satellite positioning system signals comprising:
- receiving a snippet of a reference signal, the snippet having a time of reception measured by a timing source, the reference signal being different than satellite positioning system signals that are to be used for determining position and the reference signal being different than signals from the wireless communications system;
transmitting a request for aiding information to the position determination entity, the request including the snippet and the time of reception;
receiving the requested aiding information; and
locating the satellite positioning system signals using the received aiding information;
wherein the aiding information is synchronized with the timing source.
0 Assignments
0 Petitions
Accused Products
Abstract
A system and method for providing timing information to a wireless device in a position determination system is disclosed. A wireless device includes a reference signal receiver, a signal processor, a wireless communications transceiver and a GPS receiver. The wireless device is adapted to receive a reference signal, extract a snippet of the received reference signal, determine a time of reception for the snippet and transmit the snippet and time of reception to a position determination entity as part of a request for GPS aiding information. The position determination entity includes a timing source, a GPS memory for storing GPS satellite information, a reference signal memory, a communications interface, a signal processor and a control processor. The position determination entity is adapted to continually receive and store a reference signal along with an associated time of reception, and receive the snippet and timestamp transmitted from the wireless device. The position determination entity is further adapted to match the signal snippet to a portion of the stored reference signal, determine a time offset between the timestamp and the time of reception of the matched portion of the stored reference signal, prepare aiding information for the wireless device, synchronize the aiding information to the wireless device using the time offset, and transmit the synchronized aiding information to the wireless device. The wireless device is further adapted to receive the aiding information, including timing information to assist the wireless device in acquiring the GPS signals.
36 Citations
15 Claims
-
1. In a wireless communications system including a position determination entity, a method for acquiring satellite positioning system signals comprising:
-
receiving a snippet of a reference signal, the snippet having a time of reception measured by a timing source, the reference signal being different than satellite positioning system signals that are to be used for determining position and the reference signal being different than signals from the wireless communications system; transmitting a request for aiding information to the position determination entity, the request including the snippet and the time of reception; receiving the requested aiding information; and locating the satellite positioning system signals using the received aiding information; wherein the aiding information is synchronized with the timing source. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. In a satellite positioning system (SPS) including a position determination entity, a wireless device comprising:
-
a reference signal receiver adapted to receive an RF signal; a signal processor coupled to the reference signal receiver, the signal processor adapted to extract a snippet of the RF signal and determine a time of reception at which the snippet of the RF signal was received by the reference signal receiver, the RF signal being different than SPS satellite signals that are to be used for determining position and the RF signal being different than any communications signals of the wireless device from a wireless communications network; a wireless communications transceiver adapted to transmit the snippet and time of reception to a position determination entity, and receive SPS aiding information from the position determination entity; a SPS receiver adapted to receive SPS satellite signals using the SPS aiding information; a processor; and a timing source; wherein the time of reception of the snippet is determined using the timing source; wherein the SPS aiding information includes a time offset, and wherein the processor is adapted to synchronize the timing source with the position determination entity using the time offset. - View Dependent Claims (8, 9, 10)
-
-
11. In a wireless communications network including a wireless device having a first clock and a position determination entity having a second clock a method for providing global positioning system (GPS) timing information to the wireless device, the method comprising:
-
receiving a reference signal that is different than GPS satellite signals and is different than signals from the wireless communications network; extracting a snippet of the received reference signal; determining a time of reception for the snippet according to the first clock; transmitting the snippet and the time of reception to the position determination entity; and receiving aiding information from the position determination entity, the aiding information including timing information relating to the acquisition of a satellite positioning system signal to be used for determining position, the timing information being synchronized with the first clock. - View Dependent Claims (12, 13, 14)
-
-
15. A method for acquiring satellite positioning system signals in a wireless communications system, comprising:
-
using a difference in respective times of receipt of a commonly received reference signal by a wireless communications device and a position determination entity to synchronize respective clocks thereof, the commonly received reference signal being different than signals from the wireless communications system; receiving aiding information from the position determination entity by the wireless communications device; and acquiring the satellite positioning system signals using the received aiding information, the satellite positioning system signals to be used in determining a position of the wireless communications device.
-
Specification